Method of constructing insulated conduit



Aug. 23, 1966 J. E. MALONEY 3,267,631

METHOD OF CONSTRUCTING INSULATED CONDUIT Original Filed May 3, 1961 2Sheets-Sheet 1 22 2| l6 2o 22 2| l6 28 26 I5 1 23 26 I5 I3 INVENTOR.

1 JAMES E. MALONEY F1; 5 BY ATTORNEY Aug. 23, 1966 J. E. MALONEY METHODOF CONSTRUCTING INSULATED CONDUIT 2 Sheets$heet 2 INVENTO/P JAMES E.MALONEY Original Filed May 3, 1961 ATTORNEY United States Patent3,267,681 METHOD OF CONSTRUGTING INSULATED CONDUIT ames E. Maloney, Rte.3, Madison, Wis. Original application May 3, 1961, Ser. No. 107,525, newPatent No. 3,144,050, dated Aug. 11, 1964. Divided and this applicationDec. 9, 1963, Ser. No. 328,806 4 Claims. (Cl. 6172.1)

This invention relates to improvements in insulated conduit systems andmethods of constructing the same. The present application is a divisionof my copending application S.N. 107,525, filed May 3, 1961, now PatentNo. 3,144,050.

Previous attempts to produce a satisfactory insulated conduit systemhave all resulted in products which possess one or more of severalcharacteristic disadvantages. The principal disadvantage shared by allof the insulated conduit systems now in use is their high cost ofmaterials and construction. Another disadvantage of most previoussystems is the degree of specialized skill needed to construct thesystems, often requiring trained factory personnel to supervise theconstruction. Another common disadvantage of the insulated conduitsystems presently in use is their incomplete design, thus requiring theuse of additional materials and fittings to construct an operationalsystem. A still further disadvantage of most of the insulated conduitsystems now in use is the ditficulty and expense of replacement andrepairs.

My invention has eliminated these and other existing disadvantages. Itis a primary object of my invention to provide an effective insulatedconduit system which can be constructed and maintained at a greatlyreduced cost with fewer materials, less excavation and less labor thanis required of conventional systems.

It is a further object of my invention to provide an insulated conduitsystem which can be efliciently and completely constructed at the jobsite by a contractor of normal skill and experience.

It is a still further object of my invention to provide an insulatedconduit system which is a combination of standard construction materialswith which the contractor is thoroughly familiar.

A still further object of my invention is to provide a method forconstructing an insulated conduit system which can be sealed off as theconstruction progresses.

Other objects and advantages of the invention will be apparent from thefollowing detailed explanation taken in conjunction with theaccompanying drawings wherein a preferred embodiment of the principle ofthe invention has been selected for exemplification.

In the drawings:

FIG. 1 is an elevation view of a portion of an insulated conduit of myinvention, with parts broken away.

FIG. 2 is a half-section view of an anchor for my invention.

FIG. 3 is a half-section view of a wall entrance cover plate with thewall shown in full section.

FIG. 4 is an end view of the cover plate shown in FIG. 3.

FIG. 5 is a part plan or elevation, part section view of an expansionloop for my insulated conduit system.

FIG. 6 is a sectional view of an excavation illustrating the varioussteps of my method for constructing an insulated conduit therein.

FIG. 7 is an enlarged view showing in more detail lifting means suitablefor use with my method.

Referring more particularly to the drawings in which like numbers referto like parts, FIG. 1 illustrates the insulated conduit system 10 of myinvention adopted for use as an underground heating or cooling conduitsystem. However, it is to be understood that my invention is equallywell suited for other uses including the insulated conduction of anyfluids, both below and above ground level.

My insulated conduit 10 has a continuous conduit 11 comprised of pipes12 which are fastened together in end to end abutment, preferably bymeans of circumferential butt welds 13. A tubular casing 14 consistingof rigid sections 15 of heat insulating material 16 encompases theconduit 11 in slidable contact. The heat insulating material 16 may beany structurally rigid insulating material, of which Kaylo, manufacturedby Owens- Corning Fiberglass Corporation, and Fibrocel, manufactured byJohns-Manville Co., are suitable examples. The rigid sections 15 ofinsulating material 16 are preferably semi-circular, so that twosections 15 will encompass the conduit 11 to form a completed portion ofthe tubular casing 14. However, the sections 15 may be circular toentirely encompass the conduit 11, or for larger installations, severalsections 15 may be required to encompass the conduit. It is to beunderstood that for installations requiring large diameter conduits orhigh insulating properties, the tubular casing 14 may consist ofmultiple layers of rigid insulation sections 15. It is important thatthe conduit 11 be able to slide within the tubular casing 14. This willprevent damage to the tubular casing during any movement of thecompleted conduit 11 induced by expansion and contraction of the pipes12 during periods of temperature change.

A protective envelope 17 surrounds the tubular casing 14 to complete theinsulated conduit 10, shown in FIG. 1. The protective envelope 17 iscomprised of protective strips 18, which may be made of high temperatureresistant polyvinyl chloride sheeting material weighing approximately 20ounces per square yard, or some other material having substantiallysimilar heat resistant properties. The protective strips 18 encompassthe tubular casing 14 with their sides 19 in abutment and their ends 20overlapping. The ends 20 are preferably overlapped about three inchesand sealed with an adhesive sealer 22. The abutting sides 19 of theprotective strips 18 are preefrably covered with a cover strip 21 of thesame material, which is also sealed with the adhesive sealer 22 to formthe finished protective envelope 17, which is mechanically strong andcompletely water-proof. Alternatively the protective envelope may beformed from strips of such sheeting material having an adhesive sealeror coating on one side. Such material may be wound around the tubularcasing 14 in overlapping relation with the adhesive coating facinginward to provide the desired mechanically strong and water-proofenvelope.

FIGS. 2, 3, 4 and 5 illustrate variations of my insulated conduit 10 toproduce a complete insulated conduit system. FIG. 2 shows an anchorplate 23 attached to my insulated conduit 10 to retain the conduit 11 inalignment during operation. The anchor plate 23, having a pair of sides24, is in abutment with adjacent sections 15 of the tubula casing 14.The conduit 11 is engaged in fixed relation by the anchor platealignment hole 25. An anchor sleeve 26, having cylindrical inner andouter surfaces 27 and 28 is attached to each side 24 of the anchor plate23 in substantially concentric relation to the alignment hole 25. Theanchor sleeves 26 encompass the adjacent tubular casing sections 15 infixed relation as illustrated, and are in turn enclosed within theprotective envelope 17 by means of the adhesive sealer 22, to preventthe entrance of any moisture. It is preferable that the dimensions ofthe anchor sleeve cylindrical outer surface 28 correspond to the normalouter dimensions of the tubular casing 14 so that the protectiveenvelope 17 v does not have to be modified to enclose the anchor sleeves26. FIG. 2 shows that the outer dimensions of the por tion of thetubular casing 14. encompassed by the anchor sleeves 26 are reduced tocorrespond to the dimensions of the inner surface 27 of the anchorsleeves. The anchor plate 23 is attached to suitable anchor means 29 tomaintain the conduit 11 in alignment. The anchor plate also preventslineal movement of the conduit and thereby controls the direction ofexpansion and contraction of the conduit due to temperature change.

FIGS. 3 and 4 show a cover plate 33, having a guide hole 34, attached tomy insulated conduit 14 to retain the conduit 11 in alignment as itpasses through a wall 30, which may be for a steam pit or a building.The cover plate 33 is preferably located flush with the inside surface32 of the wall 34 A cover sleeve 35 substantially similar to thepreviously described anchor sleeves 26, and

, having an outside surface 36 and an inside surface 37,

is attached to the cover plate 33, and extends through the keyed wallopening 31. Anchor dowels 38 extend outward from the cover sleeve outersurface 36 and into the wall plug 39, which is formed around the coversleeve 35 and within the keyed wall opening 31 to maintain the coverplate 33 in fixed relation to the Wall 39. In new wall construction, itmay be preferable to eliminate the wall plug 39 and keyed opening 31 andprovide for the anchor dowels to extend into the wall 30 itself. Theconduit 11 Xtl1d5 through the guide hole 34 into the building or pit inslidable relation. The tubular casing sections 15 have reduced outerdimensions to correspond to the inside surface 37 of the cover sleeve35, and extend Within the cover sleeve 35 to terminate in abutment withthe cover plate 33. The protective envelope 17 extends within the wallplug 39 to partially enclose the cover sleeve 35 and prevent anymoisture from reaching the tubular casing 14. Since the cover plate 33is maintained in a stationary position by the cover sleeve 35 and theanchor dowels 38, the guide hole 34 serves as an external guide for theconduit 11 as it enters the building or pit. If an anchor is desired atthe wall entrance, the conduit may be extended through the guide hole 34in fixed relation.

FIG. 5 illustrates an expansion loop for my insulated conduit system.The conduit 11 is shaped to form a U- shaped loop 44) having a pair ofsides 41 and a bottom section 42. The tubular casing 14 is terminatednear each side 41 of the loop 44 and resumes along the bottom section42. An expansion casing 43, substantially similar in structure andmaterial to the tubular casing 14, encases the tubular casing near eachterminating point and extends alOng each side 41 of the U-shaped loop asto encase the tubular casing along the loop bottom section 42. Anonrigid insulation material 45 such as fibrous glass is located withinthe expansion space 44 between the conduit 11 and the expansion casing43 along the expansion loop sides 41, as shown in FIG. 5. The non-rigidinsulation material 45 will allow free movement of the conduit 11 Withinthe expansion casing 43 as the main line of the conduit 11 expands andcontracts. The expansion casing 43 is completely enclosed by theenlarged protective envelope 17. It is obvious that other configurationsto provide for expansion, such as L-shaped or Z-shaped members, could besimilarly constructed.

It is apparent from the description and drawings that my insulatedconduit system is a complete system which willconduct the heating orcooling medium directly into the building where it will be used. It isalso clear that the materials which comprise my system are materialswith which all contractors are familiar as a result of their common dayto day experience. Therefore, the construction of my system fromordinary construction materials requires no special skill uncommon tobuilding contractors.

My method of constructing and installing my insulated conduit system isas follows: Excavate a ditch 5t) approximately six inches deeper thandesired lower side of the insulated conduit 10. Lay the required numberof individual pipes 12 in the ditch, though two or more lengths of pipe12 may first be circumferentially butt Welded together and then loweredinto the ditch. Place timbers 51 across the excavation at approximatelyeight foot intervals, or closer for larger size conduits. Throw a shortchain 52 over each timber above the desired cer1- ter line of theconduit 11. Place a sling 53 around the conduit beneath each shortchain. Place the hook 56 of a second short chain 55 in the metal rings54-. of the sling 53. Raise the pipes to the desired level by means ofchain jacks 57 used in conjunction with the short chains. Weld the pipes12 together in end to end abutment to form a continuous conduit 11.

At this point, there are several distinct advantages to this system ofinstallation, all resulting in a savings of cost. Elevation and gradeare easily set and held with the chain jacks. The pipes 12 are easilyaligned and held for welding with standard pipe aligners. In addition,the pipes 12 are easily rotated for ease in welding, thus reducing thenumber of position Welds to a minimum.

Rigid insulation sections 15 are next applied to the conduit Ill to formone length of tubular casing 14. Wrap the protective strips 18 aroundthe tubular casing 14 with their sides 19 in abutment and their ends 20overlapping. Retain the protective strips in the described position byapplying an adhesive sealer 22 to the overlapping ends 2%. Cover theabutting sides H with butt joint strips 21 held in place by the adhesivesealer 22 to complete the protective envelope 17 for the length of thetubular casing 14. Additional lengths of tubular casing 14 andprotective envelope 17 are added in the same manner. As the lengths ofprotective envelope 17 are completed, the adjacent slings are removedfrom the conduit 11 and repositioned around the protective envelope 17to maintain the system it in the desired position. As many feet ofinsulated conduit as desired may be suspended in this manner. The nextstep is to backfill with sand, leaving the upper half of the insulatedconduit 14? uncovered. The slings can now be removed and reused as theinstallation progresses. An air test of suitable pressure on the conduit11 is recommended at this time. Where it is convenient, the air testshould be made before adding the insulation 16. Backfilling with sand iscontinued to a level six inches over the top of the protective envelope17. The remaining backfilling is by conventional means, using excavateddirt.

It is apparent from the foregoing description that construction of myinsulated conduit system can progress in stages resulting in greaterconstruction speed due to the permitted division of the work force, andallowing the job to be sealed off after each day of work. Anchors andexpansion loops can be provided Within my system in the conventionalmanner. However, because of the complete freedom of movement inherent inmy system, anchors are seldom needed.

Use of my insulated conduit system and method of construction requiresless materials, less excavation, and less care in making the excavation,all of which reduce the cost below that of other existing systems.

It is understood that the present invention is not confined to theparticular construction and method herein excavating a ditch deeper thanthe desired lower line of the conduit, placing a necessary number ofpipe. sections in,

said ditch, placing a plurality of supporting members across said ditch,suspending adjustable lifting means from each of said supportingmembers, connecting a plurality of said lifting means to each of saidpipe sections in supporting relation, raising the pipe sections to thedesired level by operation of said adjustable lifting means, connectingthe ends of said pipe sections to form a pipe, covering a portion ofsaid pipe between said lifting means with a plurality of structurallyrigid insulation sections to form a length of tubular casing whichencloses said pipe in slidable relation, wrapping said tubular casingwith a heat resistant protective material to form a protective envelope,removing said lifting means adjacent to said length of tubular casingfrom said pipe and repositioning said lifting means around said tubularcasing and protective envelope to maintain said pipe at the desiredlevel, continuing the construction of said tubular casing and saidprotective envelope until the entire length of pipe is enclosed inslidable relation to form an insulated conduit at the desired level andgrade, filling said ditch until said insulated conduit is supported bysaid fill, removing said lifting means from said insulated conduit,filling said ditch to cover said insulated conduit.

2. The method described in claim 1 wherein the heat resistant protectivematerial has an adhesive coating on one side thereof, and wherein saidprotective material is wound around the tubular casing in overlappingrelation with said adhesive coating facing inward to provide amechanically strong, substantially moisture-proof envelope.

3. The method described in claim 1 wherein the heat resistant protectivematerial comprises a plurality of strips, and wherein the ends of saidstrips are covered with an adhesive sealer and overlapped to form amechanically strong, substantially moistureproof envelope.

4. The method of constructing an insulated conduit for the undergrounddistribution of fluids which comprises, excavating a ditch deeper thanthe desired lower line of the conduit, placing a necessary number ofpipe sections in said ditch, placing supporting members across saidditch, attach a first short chain to each supporting member above thedesired center line of said conduit, placing a sling having a pair ofsupport rings around the pipes beneath each first chain, placing thehook of a second short chain through the support rings of each of saidslings, raising the pipes to the desired level and grade by means ofchain jacks used in conjunction with said first and second short chains,connecting the ends of said pipe sections to form a pipe, covering aportion of said pipe between said slings With a plurality ofstructurally rigid insulation sections to form a length of tubularcasing which encloses said pipe in slidable relation, wrapping saidtubular casing with a heat resistant protective material to form aprotective envelope, removing the slings adjacent to said length oftubular casing from said pipe and repositioning said slings around saidprotective envelope to maintain said pipe at the desired level andgrade, continuing the construction of said tubular casing and saidprotective envelope until the entire length of pipe is enclosed in slidable relation to form an insulated conduit, filling said ditch until saidinsulated conduit is supported by said fill, removing said slings fromsaid insulated conduit, filling said ditch to cover said insulatedconduit.

References Cited by the Examiner UNITED STATES PATENTS 1,600,701 9/1926Summer 6172.1 2,355,966 8/1944 Grotl l38100 2,707,984 5/1955 Grotf138l06 X 2,987,981 6/1961 Phillips 6l72.1 3,101,530 8/1963 Coscia 6172.1X

EARL J. WITMER, Primary Examiner.

1. THE METHOD OF CONSTRUCTING AN INSULATED CONDUIT FOR THE UNDGERGROUNDDISTRIBUTION OF FLUIDS WHICH COMPRISES, EXCAVATING A DITCH DEEPER THANTHE DESIRED LOW LINE OF THE CONDUIT, PLACING A NECESSARY NUMBER OF PIPESECTIONS IN SAID DITCH, PLACING A PLURALITY OF SUPPORTING MEMBERS ACROSSSAID DITCH, SUSPENDING ADJUSTABLE LIFTING MEANS FROM EACH OF SAIDSUPPORTING MEMBERS, CONNECTING A PLURALITY OF SAID LIFTING MEANS TO EACHOF SAID PIPE SECTIONS IN SUPPORTING RELATION, RAISING THE PIPE SECTIONSTO THE DESIRED LEVEL BY OPERATION OF SAID ADJUSTABLE LIFTING MEANS,CONNECTING THE ENDS OF SAID PIPE SECTIONS TO FORM A PIPE, COVERING APORTION OF SAID PIPE BETWEEN SAID LIFTING MEANS WITH A PLURALITY OFSTRUCTURALLY RIGID INSULATION SECTIONS TO FORM A LENGTH OF TUBULARCASING WHICH ENCLOSES SAID PIPE IN SLIDABLE RELATION, WRAPPING SAIDTUBULAR CASING WITH A HEAT RESISTANT PROTECTIVE MATERIAL TO FORM APROTECTIVE ENVELOPE, REMOVING SAID LIFTING MEANS ADJACENT TO SAID LENGTHOF TUBULAR CASING FROM SAID PIPE AND REPOSITIONING SAID LIFTING MEANSAROUND SAID TUBULAR CASING AND PROTECTIVE ENVELOPE TO MAINTAIN SAID PIPEAT THE DESIRED LEVEL, CONTINUING THE CONSTRUCTION OF SAID TUBULAR CASINGAND SAID PROTECTIVE ENVELOPE UNTIL THE ENTIRE LENGTH OF PIPE IS ENCLOSEDIN SLIDABLE RELATION TO FORM AN INSULATED CONDUIT AT THE DESIRED LEVELAND GRADE, FILLING SAID DITCH UNTIL SAID INSULATED CONDUIT IS SUPPORTEDBY SAID FILL REMOVING SAID LIFTING MEANS FROM SAID INSULATED CONDUIT,FILLING SAID DITCH TO COVER SAID INSULATED CONDUIT.